How Do Self Watering Pots Work?
Using self-watering pots is convenient, efficient, and promotes plant health. These planters and pots use wicking action to deliver water from a built-in reservoir, allowing you to water your plants without constantly monitoring the soil’s moisture level, which is ideal for those who don’t have much time to water.
The self-watering pots work by wicking to bring the soil into contact with the water. They include a growing bed, potting soil, and water reservoir. Soil wicks up more water as the plant roots absorb it, ensuring the soil remains at the recommended moisture level.
Self-watering pots, also called sub-irrigation containers, have gained popularity because they are very effective and easy to maintain. There are many style options available to choose from, from which you can build them yourself using inexpensive, readily available materials.
Self-watering pots have endless design possibilities, but the four basic elements described above always come together to form an elegant houseplant care solution ideal for today’s rushed lifestyles.
The self-watering pot trend has exploded on the scene in recent years because it makes sense once you know how these pots work. We’ve put together an in-depth guide on how self-watering pots work in the hope that you’ll be inspired to try them.
Capillary Action (Wicking) Explained
Self-watering pots work by drawing water from a surface by using a principle called capillary action. Capillary action is known to explain how sponges draw liquid, hairs on a paintbrush draw paint, and wicks draw up wax. Plants, including even the tallest trees, accomplish this feat of overcoming gravity to pull water up from their roots to the top of the plant.
The capillary action of liquids is the result of both intermolecular activities of molecules and the attractions between a liquid and a solid that has narrow tubes or small spaces inside it. Unlike cohesion, which is the attraction between like molecules of a liquid, adhesion occurs between molecules that are unlike one another. It is similar to how dewdrops cling to a leaf or flower.
In cases where the adhesive force between the liquid and the solid is greater than the cohesive force within the liquid, as is the case when the cracks between solid walls are sufficiently small, the liquid will be propelled within these cracks.
Plants in self-watering pots need to receive a thorough watering of the soil when they are planted. Then, as they release water from their leaves, they pull water up from the roots through capillary action to replace it.
Capillary action ingests water from the bottom of the reservoir, replacing it with water contained in the soil through the roots, which is also continually supplied from the soil by the roots. The soil remains consistently moist and not waterlogged with the appropriate potting mixture and wicking mechanism.
The Four Basic Elements Of A Self-Watering Pot
It doesn’t matter if it’s a single plant or a large container garden, self-watering pots always have the same four components:
Growing beds hold the potting soil and the plants on higher levels of the container.
To ensure success with a self-watering pot, you need to use soil that is lightweight and absorbent, whether it is soil or another form of growing medium such as coco coir, perlite, or growstones.
The key is to choose something that consistently pulls water from the ground while also providing plenty of oxygen to the plant roots.
A self-watering pot contains a reservoir below the growing bed. Since you can’t see the reservoir, a viewing window or float will allow you to monitor the water level, eliminating the need for an overflow outlet for indoor planters.
Additionally, the reservoir must be able to be filled, either through a vertical line filling it from above or through an opening on its side.
Providing separate areas for the growing bed and the water reservoir may be done by placing a container in the pot’s bottom, by designing a barrier within the pot, or by using two pots: one for the growing bed and one for the reservoir.
By means of the wicking system, water is delivered from the reservoir to the soil and then to the roots of the plants. It is either possible to use absorbent materials such as ropes or strips of cloth that are situated with one end in water and the other in soil or you can implement a wicking pot that places the potting mixture directly in contact with the water in the reservoir.
We will examine each of these wicking systems in the following two sections.
Self-Watering Pot Wicks
Using wicks, you can easily move the water from the reservoir to your potting soil. Wicks can be made from almost any absorbent material, including cotton, wool, felt, nylon, polyurethane, and microfiber.
If your intention is to use the material over a long period of time, however, it is better to use a durable, rot-resistant material such as the fiberglass wick that is used for oil lamps and candle making and that can be found at many gardening suppliers.
A self-watering pot must have wicks that reach the reservoir’s bottom so that they are always in contact with the water, even when the level of the reservoir is low.
You should extend the wicks into the soil rather than placing them on the bottom of the growing bed. To do this, simply hold the top end up as you pour the potting soil into the container.
In order to determine how many wicks you need, you will need to consider factors such as the size of the container, the type of potting soil, type of wicking material, number, and type of plants.
According to the general rule, you need two wicks per plant. However, you should test the system out with your soil to verify its effectiveness. If your plants have not been getting adequate water, you may need to make adjustments.
Self-watering pots that use wicking systems are often referred to as “wicking pots.” Wicking pots are self-watering planters with the soil in direct contact with the water, separated only by a permeable barrier.
Most self-watering pots actually function as wicks in and of themselves. It is this principle that causes some self-watering wicking pots to enable you to convert a regular flowerpot into a self-watering pot by adding a water container to the bottom of the pot that has a perforated top which functions as the growing bed.
Alternatively, you can create a wicking pot by filling a basket with potting soil and extending it down from the growing bed into the reservoir. Use a container with an opening that allows the soil to contact the water, such as a basket or other container with an opening. An interior lining made of mesh, window screening, or another thin, permeable fabric ensures soil is kept out.
It is possible to create a self-watering wicking pot by putting gravel or sand in the bottom third of a container that does not have drainage holes, then covering it with permeable cloth until it is completely full.
Shade cloth can be made with anything from old sheets or T-shirts to reusable shopping bags. Watering shafts can be made with a PVC pipe inserted before filling in the soil. You will need to cut a hole in the fabric for this.